dt-bindings: mediatek: add descriptions for larbid

This patch add larbid descritptions for mediatek's gen1 smi larb hardware.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Honghui Zhang <honghui.zhang@mediatek.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Documentation/devicetree/bindings/memory-controllers/mediatek,smi-larb.txt

@@ -15,6 +15,9 @@ Required properties:
 	    the register.
   - "smi" : It's the clock for transfer data and command.
 
+Required property for mt2701:
+- mediatek,larb-id :the hardware id of this larb.
+
 Example:
 	larb1: larb@16010000 {
 		compatible = "mediatek,mt8173-smi-larb";
@@ -25,3 +28,15 @@ Example:
 			 <&vdecsys CLK_VDEC_LARB_CKEN>;
 		clock-names = "apb", "smi";
 	};
+
+Example for mt2701:
+	larb0: larb@14010000 {
+		compatible = "mediatek,mt2701-smi-larb";
+		reg = <0 0x14010000 0 0x1000>;
+		mediatek,smi = <&smi_common>;
+		mediatek,larb-id = <0>;
+		clocks = <&mmsys CLK_MM_SMI_LARB0>,
+			 <&mmsys CLK_MM_SMI_LARB0>;
+		clock-names = "apb", "smi";
+		power-domains = <&scpsys MT2701_POWER_DOMAIN_DISP>;
+	};